排序字段+0,类似 Java 把 其他类型转换成字符串 比如 +“”；
SELECT
b.tag_value AS NAME,
sum(b.uv) AS
VALUE
FROM
meta.dic_app_category a,
rpt_app_cat_people b
WHERE
a.id = b.`name`
AND a.id = 100
AND b.tag_name = ‘active_hour‘
GROUP BY
b.tag_value
ORDER BY
(b.tag_value + 0) ASC
原文：http://www.cnblogs.com/zgghb/p/5580130.html